Structure and expression of human IFN-alpha genes.

Area of Science:

• Molecular Biology
• Immunology
• Genetics

Background:

• Interferons (IFNs) are crucial for antiviral responses.
• Understanding IFN-alpha gene structure and evolution is key to their therapeutic application.

Purpose of the Study:

• To clone and characterize human interferon-alpha (IFN-alpha) complementary DNA (cDNA).
• To investigate the human IFN-alpha gene family and its evolutionary history.
• To express functional IFN-alpha in bacterial and mammalian systems.

Main Methods:

• cDNA cloning from induced leucocyte poly(A) RNA in Escherichia coli.
• Translation hybridization assays for clone identification.
• Screening of a human chromosomal library with IFN cDNA.
• Gene sequencing and phylogenetic analysis.
• Expression of IFN-alpha genes in E. coli and mammalian cell lines.

Main Results:

• Isolation and identification of multiple IFN-alpha cDNA clones encoding mature polypeptides and signal sequences.
• Characterization of the human IFN-alpha gene family, including authentic genes, pseudogenes, and allelic variants.
• Classification of IFN-alpha genes into two subfamilies with ancient divergence.
• Successful expression of mature IFN-alpha in E. coli and functional IFN-alpha production in engineered hamster cells.
• Demonstration of hybrid IFN gene specificities and expression of human IFN-alpha in mouse cells.

Conclusions:

• The human genome contains a complex family of IFN-alpha genes with significant evolutionary history.
• Recombinant DNA technology allows for the high-yield production of functional IFN-alpha in prokaryotic and eukaryotic systems.
• Engineered mammalian cells can constitutively produce biologically active interferons, offering therapeutic potential.